During the coming year available data will be analyzed with the assistance of a biostatistician. The following hypotheses will be evaluated: (a) young children infected with hepatitis B virus (HBV) are at increased risk of becoming carriers of HBsAg, (b) HBV is in dynamic equilibrium with this population, (c) does HBeAg associate with long-term carriers of HBsAg? (d) presence of anti-HBe leads to clearing of HBsAg from the circulation.